A surrounding test device

Abstract

This invention relates to a confining pressure testing device for testing cubic rock blocks. It includes an outer shell and multiple confining pressure units, each unit comprising a pressure pad, an inner pad block, an outer pad block, an inner bladder, and a connector. The pressure pad is embedded in the inner and outer pad blocks; the inner pad block is not fixedly connected to the pressure pad, while the outer pad block is fixedly connected to the pressure pad. The connector connects the outer pad block to the outer shell. Multiple inner pad blocks surround the rock block. The pressure pad has a laminated structure. The pressure pad, the inner pad block, and the outer pad block form a closed cavity. The inner bladder is disposed within the cavity. After being filled with fluid and expanding, the inner bladder adheres tightly to the inner surface of the cavity. Pressure is transmitted to the rock block through the inner pad blocks, forming confining pressure on the rock block. This invention reduces the deformation and weight of the confining pressure testing device through structural optimization and material improvements to the pressure pad.

Description

Technical Field

[0001] This invention relates to the field of geotechnical exploration equipment technology, and in particular to a confining pressure testing device that can be used for confining pressure testing of cubic rock specimens. Background Technology

[0002] In rock mechanics testing, confining pressure is required to simulate the pressure environment of rocks underground. The mechanical properties of rocks change significantly with variations in confining pressure. Currently, confining pressure testing equipment used in related technologies is typically made of metallic materials such as titanium alloys. Using titanium alloys as a material results in high cost and heavy weight. Furthermore, in traditional confining pressure testing equipment, the connection between the pressure pad and the pad block used to apply the confining pressure relies solely on friction, leading to significant deformation of the pressure pad, affecting the reliability of the confining pressure test, and increasing the design thickness of the pressure pad.

[0003] Therefore, it is necessary to develop a new type of confining pressure testing device to reduce weight, lower costs, reduce deformation, and improve the reliability of confining pressure testing.

[0004] It should be noted that the information disclosed in this background section is intended only to enhance the understanding of the overall background of the present invention, and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art.

[0005] The present invention aims to provide a confining pressure testing device for rocks to solve the problems of high material cost, heavy weight and significant deformation of existing confining pressure testing equipment.

[0006] The technical solution adopted by this invention to solve the technical problem is as follows: To reduce the weight and deformation of the pressure pad, this invention first considers using a material with greater stiffness as the pressure pad material, such as carbon fiber, which is a good choice. Secondly, this invention seeks structural improvements to the confining pressure device to further reduce the weight and deformation of the structure. Considering that the pressure pad is a thin-walled structure, the effect of pressure on a thin-walled structure includes two aspects: the effect of force and the effect of torque. In the applicant's preliminary research, it was found that the effect of torque has a significant impact on the deformation of thin-walled structures. This invention changes the rotation center of structural deformation by modifying the structural design of the pressure pad and its connection method with the pad block, thereby reducing the torque generated by pressure, which will have a very good effect on reducing the deformation of the thin-walled structure.

[0007] To achieve the above objectives, the present invention specifically adopts the following technical solution:

[0008] A confining pressure testing device for testing cubic rock blocks includes: an outer shell and multiple confining pressure units. The outer shell forms an internal receiving space, and the multiple confining pressure units are arranged within the receiving space. Each confining pressure unit includes a pressure pad, an inner pad block, an outer pad block, an inner bladder, and a connector. The pressure pad is positioned between the inner pad block and the outer pad block, embedded in both blocks. The pressure pad is fixedly connected to the outer pad block, and non-fixedly connected to the inner pad block. The connector is used for... The outer pad is connected to the outer shell, and multiple inner pads surround the periphery of the cubic rock block; the pressure pad is a laminated structure, including an outer layer of thin-walled metal structure and an inner layer of carbon fiber composite material laminated structure; a sealed cavity is formed between the pressure pad and the surfaces of the inner and outer pads, and the inner bladder is arranged in the cavity. The inner bladder is a hollow elastic element. After the inner bladder is filled with fluid, it expands and closely adheres to the surfaces of the pressure pad, the inner pads, and the outer pads. The pressure is transmitted to the rock block through the inner pads, forming a confining pressure on the cubic rock block.

[0009] In the aforementioned confining pressure testing device, the pressure pad includes: a first curved surface that mates with the inner bladder, and a first flange and a second flange respectively arranged on both sides of the first curved surface. The first flange and the second flange are respectively embedded inside the inner pad block and the outer pad block. By embedding the pressure pad into the inner and outer pad blocks, the structural deformation of the pressure pad after bearing pressure can be effectively reduced.

[0010] In the aforementioned confining pressure test device, the processing technology of the pressure pad is as follows: the metal thin-walled structure is used as the mold for curing the inner carbon fiber composite laminate structure; the carbon fiber composite prepreg is cut and laid on the inner surface of the outer metal thin-walled structure, compacted with a vacuum bag, and placed in an autoclave for curing; the carbon fiber composite laminate structure does not need to be demolded from the metal thin-walled structure, and becomes a whole after curing.

[0011] In the aforementioned confining pressure testing device, a waist-shaped first screw hole is provided on the first flange, allowing the inner pad to slide relative to the pressure pad. After the inner bladder is filled with fluid and expands, the inner pad can move towards the rock block to achieve confining pressure.

[0012] In the aforementioned confining pressure testing device, the inner pad is a square block. One surface of the inner pad contacts the rock block, and the other surface has a first groove structure that mates with the first flange. A first outer screw hole and a first inner screw hole are respectively arranged on both sides of the first groove structure. Screws pass through the first outer screw hole, the first screw hole, and the first inner screw hole in sequence. A threaded structure is provided in the first inner screw hole to achieve the connection between the inner pad and the pressure pad. The inner pad is embedded and installed by means of the groove structure and screws arranged on the inner pad.

[0013] In the aforementioned confining pressure testing device, the outer pad and the connecting member are slidably connected via a first mortise and tenon joint, and the connecting member and the outer shell are slidably connected via a second mortise and tenon joint. The first mortise and tenon joint allows the outer pad to slide relative to the connecting member; the second mortise and tenon joint allows the connecting member to slide relative to the outer shell. This detachable connection between the outer pad and the connecting member, and between the connecting member and the outer shell, through the mortise and tenon joint structure simplifies the connection structure of the confining pressure testing device, reduces the number of parts, and makes installation more convenient.

[0014] In the aforementioned confining pressure testing device, the inner bladder is made of rubber, and its shape is designed to conform to the surface shape of the sealed cavity formed between the pressure pad, the inner pad block, and the outer pad block. A one-way valve is provided at the entrance of the inner bladder, and the one-way valve passes through the pressure pad and connects to an external fluid source. The one-way valve is used to inject fluid, and the magnitude of the confining pressure is adjusted by changing the elastic deformation of the inner bladder.

[0015] In the aforementioned confining pressure testing device, the outer shell is a cylindrical shell structure, the surface of the connector that contacts the outer pad is a plane, and the surface of the connector that contacts the outer shell is a cylindrical curved surface. Attached Figure Description

[0016] The accompanying drawings are provided to further understand the invention and constitute a part of this invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0017] Figure 1 According to some embodiments of this application, a three-dimensional structural schematic diagram of a confining pressure test apparatus is shown;

[0018] Figure 2 A schematic diagram of the structure of the pressure pad is shown according to some embodiments of this application;

[0019] Figure 3 According to some embodiments of this application, a structural schematic diagram of the inner pad block is shown;

[0020] Figure 4 According to some embodiments of this application, a structural schematic diagram of the side of the outer pad that contacts the pressure pad is shown;

[0021] Figure 5 According to some embodiments of this application, a structural schematic diagram of the side of the outer pad block in contact with the connector is shown;

[0022] Figure 6 A schematic diagram of the internal capsule structure is shown according to some embodiments of this application;

[0023] Figure 7 According to some embodiments of this application, a structural schematic diagram of the side of the connector that contacts the outer pad is shown;

[0024] Figure 8 According to some embodiments of this application, a structural schematic diagram of the side of the connector that contacts the housing is shown;

[0025] Figure 9 According to some embodiments of this application, a structural schematic diagram of the outer casing is shown;

[0026] Explanation of reference numerals in the attached figures:

[0027] 10. Pressure pad; 11. First curved surface; 12. First flange; 13. Second flange; 14. Thin-walled metal structure; 15. Carbon fiber composite laminate structure; 16. First screw hole; 17. Second screw hole; 18. One-way valve hole; 20. Inner pad; 21. First groove structure; 22. First outer screw hole; 23. First inner screw hole; 30. Outer pad; 31. Second groove structure; 32. First groove; 33. Second outer screw hole; 34. Second inner screw hole; 40. Inner bladder; 41. Flat surface; 42. Second curved surface; 43. One-way valve; 50. Connector; 51. Flat surface; 52. First flange; 53. Cylindrical curved surface; 54. Second groove; 60. Outer shell; 61. Inner surface; 62. Second flange; 70. Screw; 80. Rock block. Detailed Implementation

[0028] The technical features and advantages of the present invention will be described in more detail below with reference to the accompanying drawings and embodiments, so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making a clearer and more explicit definition of the scope of protection of the present invention.

[0029] Please see Figures 1-9This invention provides a confining pressure testing device for testing rock blocks. The device comprises an outer shell 60 and multiple confining pressure units. The interior of the outer shell 60 forms a receiving space, within which the multiple confining pressure units are spaced apart. These units enclose and form a confining pressure on a cubic rock block 80. To facilitate a more uniform confining pressure, the outer shell 60 can be designed as a cylindrical shell structure, with four confining pressure units evenly arranged radially inside the outer shell 60. Each confining pressure unit includes: a pressure pad 10, an inner pad 20, an outer pad 30, an inner bladder 40, and a connector 50. The pressure pad 10 is positioned between the inner pad 20 and the outer pad 30, embedded within them. The pressure pad 10 is fixedly connected to the outer pad 30 but not fixedly connected to the inner pad 20. The connector 50 connects the outer pad 30 to the outer shell 60. The multiple inner pads 20 enclose the cubic rock block 80. The pressure pad 10 and the surfaces of the inner pad 20 and outer pad 30 form a closed cavity. The inner bladder 40 is arranged in the closed cavity. After the inner bladder 40 is extended, it is in close contact with the surfaces of the pressure pad 10, the inner pad 20 and the outer pad 30, thereby transmitting pressure to the rock block 80 through the inner pad 20, forming a confining pressure on the rock block 80. By adjusting the volume or pressure of the fluid injected into the inner bladder 40, the elastic deformation of the inner bladder 40 is changed, thereby adjusting the magnitude of the confining pressure on the rock block 80.

[0030] In this embodiment of the invention, the pressure pad 10 is a laminated structure, comprising an outer metal thin-walled structure 14 and an inner carbon fiber composite laminated structure 15. By using carbon fiber composite material as the material for the pressure pad 10, the weight of the structure can be effectively reduced while ensuring structural strength and stiffness, and material costs can be lowered. In a preferred processing method, the outer metal thin-walled structure 14 serves as the mold for curing the carbon fiber composite laminated structure 15. The carbon fiber composite prepreg is cut and laid on the inner surface of the metal thin-walled structure 14, compacted with a vacuum bag, and placed in an autoclave for curing. The carbon fiber composite laminated structure 15 does not require demolding from the metal thin-walled structure 14 and becomes a single unit after curing. As an example, the metal thin-walled structure 14 in this embodiment of the invention can be made of titanium alloy.

[0031] Furthermore, to reduce the torque generated by the structure under pressure, thereby reducing structural deformation, this embodiment of the invention optimizes the connection structure between the pressure pad 10 and the inner pad 20 and outer pad 30. The pressure pad 10 is generally square with rounded corners that smoothly transition at the four corners. The pressure pad 10 includes a first curved surface 11 in the middle and flanged portions arranged on both sides of the first curved surface 11, namely a first flanged portion 12 embedded in the inner pad 20 and a second flanged portion 13 embedded in the outer pad 30. The first flanged portion 12 and the second flanged portion 13 are respectively designed with screw holes, which are used to cooperate with screws 70 to connect the pressure pad 10 with the inner pad 20 and the outer pad 30. In order to achieve a non-fixed connection between the pressure pad 10 and the inner pad 20, the first screw hole 16 on the first flanged portion 12 is designed as a waist shape, which allows the inner pad 20 to slide relative to the pressure pad 10 after the inner bladder 40 is extended. The second screw hole 17 of the second flange portion 13 embedded in the outer pad 30 is circular and is used to cooperate with the screw 70 to achieve a fixed connection between the pressure pad 10 and the outer pad 30.

[0032] To accommodate the side structure of the rock block 80, the inner pad 20 is a square block. A first groove structure 21 is provided on the surface of the inner pad 20 that mates with the pressure pad 10. The first flange 12 of the pressure pad 10 is embedded in the first groove structure 21. A first outer screw hole 22 and a first inner screw hole 23 are respectively provided on both sides of the first groove structure 21. The screw 70 passes through the first outer screw hole 22 and the first screw hole 16 of the first flange 12, connecting with the first inner screw hole 23. The first inner screw hole 23 has a threaded hole that mates with the screw 70. Both the first outer screw hole 22 and the first screw hole 16 are unthreaded through holes, allowing the inner pad 20 to slide relative to the pressure pad 10 even after the screw 70 is installed. The surface of the inner pad 20 facing away from the pressure pad 10 is in direct contact with the surface of the rock block 80.

[0033] The outer pad 30 is a square block. A second groove structure 31 is provided on the surface of the outer pad 30 that mates with the pressure pad 10. The second flange 13 of the pressure pad 10 is embedded in the second groove structure 31. A second outer screw hole 33 and a second inner screw hole 34 are respectively provided on both sides of the second groove structure 31. A screw 70 passes through the second outer screw hole 33 and the second screw hole 17 of the second flange 13, connecting to the second inner screw hole 33. The second inner screw hole 33 has a threaded hole that mates with the screw 70. Both the second outer screw hole 33 and the second screw hole 17 are unthreaded through holes. The pressure pad 10 and the outer pad 30 are fixedly connected by the screw 70. The surface of the outer pad 30 facing away from the pressure pad 10 is mounted on the outer casing 60 via a connector 50.

[0034] The inner bladder 40 is a hollow, elastic extension member that can be made of rubber. Its external shape is adapted to the shape of the sealed cavity formed between the inner pad 20, the pressure pad 10, and the outer pad 30. Specifically, it includes a flat portion 41 that mates with the inner pad 20 and the outer pad 30, and a second curved portion 42 that mates with the pressure pad 10. The second curved portion 42 mates with the first curved portion 11 of the pressure pad 10. A one-way valve 43 communicating with the hollow cavity is provided on the second curved portion 42. The one-way valve 43 extends out of the pressure pad 10 through a one-way valve hole 18 on the pressure pad 10. The one-way valve 43 is used to inject fluid, and the confining pressure value is changed by adjusting the pressure of the fluid.

[0035] For ease of installation, the connector 50 is connected to the outer pad 30 and to the outer casing 60 via mortise and tenon joints, and can be slidably detached. The side of the connector 50 that contacts the outer pad 30 is a flat surface 51, on which a first flange 52 is designed. The outer pad 30 has a corresponding first groove 32 that mates with the first flange 52. The side of the connector 50 that contacts the outer casing 60 is a cylindrical curved surface 53, on which a second groove 54 is designed. The outer casing 60 has a corresponding second flange 62 that mates with the second groove 54.

[0036] To provide uniform confining pressure, the outer shell 60 can be designed as a cylindrical shell structure. The inner surface of the cylindrical shell is provided with eight second flanges 62 at intervals, and each pair of second flanges 62 cooperates with the two second sliding grooves 54 of the connector 50.

[0037] In other embodiments, the outer shell 60 can also be designed as a regular polygonal shell structure. In this case, the side of the connector 50 that mates with the outer shell 60 can be designed as a plane. The outer shell 60 acts as a fixing member. After the inner bladder 40 is filled with fluid and expands, it applies confining pressure to the rock block 80 through the inner pad block 20.

[0038] The confining pressure testing device of this invention is used / installed as follows:

[0039] 1. First, the first flange 12 and the second flange 13 of the pressure pad 10 are respectively embedded into the first groove structure 21 of the inner pad block 20 and the second groove structure 31 of the outer pad block 30, and the inner bladder 40 is arranged in the sealed cavity formed by them.

[0040] 2. Connect the pressure pad 10 to the inner pad 20 and the outer pad 30 using screws 70;

[0041] 3. Arrange the four sets of connected pressure pads 10, inner pads 20, outer pads 30 and inner bladders 40 (i.e. confining pressure units) on the four sides of the rock block 80 respectively;

[0042] 4. Four connectors 50 are slid in through mortise and tenon joints to form a connection between the four outer pads 30 and the outer shell 60;

[0043] 5. Fluid is simultaneously injected into the four inner bladders 40 through the one-way valve 43;

[0044] 6. Under the push of the inner bladder 40, the four inner pads 20 slide towards the four sides of the rock block 80, forming confining pressure.

[0045] The confining pressure test device of this invention, through material improvement and structural optimization, achieves weight reduction and effective control of deformation, and effectively improves the reliability of rock confining pressure tests.

[0046] In the description of the embodiments of the present invention, it should be understood that the terms "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "center," "top," "bottom," "top," "bottom," "inner," "outer," "inner side," and "outer side," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the purpose of describing the present invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. "Inner side" refers to the interior or enclosed area or space. "Outer perimeter" refers to the area surrounding a specific component or specific area.

[0047] In the description of embodiments of the present invention, the terms "first," "second," "third," and "fourth" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first," "second," "third," or "fourth" may explicitly or implicitly include one or more of that feature. In the description of the present invention, unless otherwise stated, "a plurality of" means two or more.

[0048] In the description of the embodiments of the present invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "assembly" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in the present invention based on the specific circumstances.

[0049] In the description of embodiments of the present invention, specific features, structures, materials or characteristics may be combined in any suitable manner in one or more embodiments or examples.

[0050] In the description of the embodiments of the present invention, it should be understood that "-" and "~" represent a range of two numerical values, and this range includes the endpoints. For example, "AB" represents a range greater than or equal to A and less than or equal to B. "A~B" represents a range greater than or equal to A and less than or equal to B.

[0051] In the description of embodiments of the present invention, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0052] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A confining pressure testing apparatus, applied to confining pressure testing of cubic rock blocks, characterized in that, include: An outer shell, the interior of which forms a receiving space; Multiple confining pressure units are arranged within the accommodating space. Each confining pressure unit includes a pressure pad, an inner pad block, an outer pad block, an inner bladder, and a connector. The pressure pad is positioned between the inner and outer pad blocks, both of which are embedded within it. The pressure pad is fixedly connected to the outer pad block, but not fixedly connected to the inner pad block. The connector connects the outer pad block to the outer shell. Multiple inner pad blocks surround the periphery of the cubic rock block. The pressure pad has a laminated structure, comprising an outer thin-walled metal structure and an inner carbon fiber composite material laminate. A sealed cavity is formed between the pressure pad and the surfaces of the inner and outer pad blocks. The inner bladder is arranged within the cavity and is a hollow elastic element. When filled with fluid, the inner bladder expands and adheres tightly to the surfaces of the pressure pad, inner and outer pad blocks. Pressure is transmitted to the rock block through the inner pad block, creating confining pressure on the cubic rock block.

2. The confining pressure testing apparatus according to claim 1, characterized in that, The pressure pad includes: a first curved surface that mates with the inner bladder, a first flange and a second flange respectively arranged on both sides of the first curved surface, the first flange and the second flange being respectively embedded in the interior of the inner pad block and the outer pad block.

3. The confining pressure testing apparatus according to claim 1, characterized in that, The processing technology of the pressure pad is as follows: the metal thin-walled structure is used as the mold for curing the inner carbon fiber composite laminate structure. The carbon fiber composite prepreg is cut and laid on the inner surface of the outer metal thin-walled structure, compacted with a vacuum bag, and placed in a thermostatic precipitator for curing. After curing, it becomes a whole.

4. The confining pressure testing apparatus according to claim 2, characterized in that, The first flange is provided with a waist-shaped first screw hole, through which the inner pad block can slide relative to the pressure pad.

5. The confining pressure testing apparatus according to claim 4, characterized in that, The inner pad is a square block. One side of the inner pad is in contact with the rock block, and the other side has a first groove structure that mates with the first flange. A first outer screw hole and a first inner screw hole are respectively arranged on both sides of the first groove structure. The screw passes through the first outer screw hole in sequence, and the first screw hole and the first inner screw hole are connected. The first inner screw hole is provided with a thread.

6. The confining pressure testing apparatus according to claim 1, characterized in that, The outer pad and the connector are slidably connected by a first tenon and mortise connection structure, and the connector and the outer shell are slidably connected by a second tenon and mortise connection structure.

7. The confining pressure testing apparatus according to claim 2, characterized in that, The inner bladder is made of rubber, and its shape is designed to conform to the surface shape of the sealed cavity formed between the inner surface of the pressure pad, the inner pad block, and the outer pad block. A one-way valve is provided at the entrance of the inner bladder, and the one-way valve passes through the pressure pad and connects to an external fluid source.

8. The confining pressure testing apparatus according to claim 1, characterized in that, The outer shell is a cylindrical shell structure; the surface of the connector that mates with the outer pad is a plane, and the surface of the connector that mates with the outer shell is a cylindrical curved surface.

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